Microporous Organic Framework Research Articles

Exceptionally Stable Microporous Organic Frameworks with Rigid Building Units for Efficient Small Gas Adsorption and Separation.

Three microporous organic frameworks (hereafter denoted as MPOF-Ads) based on a rigid adamantane core have been successfully synthesized via Sonogashira-Hagihara polycondensation coupling in high yields, 83.7-94.6%. The obtained amorphous MPOF-Ads networks have high Brunauer-Emmett-Teller surface areas (up to 737.3 m2 g-1), narrow pore size distribution (0.95-1.06 nm), and superior thermal (the initial decomposition temperature T5% under an N2 atmosphere can reach 410 °C) and chemical stability (no apparent degradation in common organic solvents or strong acid/base solutions after 7 days). At 273 K and 1.0 bar, these MPOF-Ads networks present good uptake capacities for small gas molecules (13.9 wt % CO2 and 1.66 wt % CH4) for which the presence of high surface area, predominant microporosity, and narrow pore size distribution are beneficial. In addition, the as-prepared MPOF-Ads networks possess moderate isosteric heats for CO2 (Qst = 19.5-30.3 kJ mol-1) and show desired CO2/N2 and CO2/CH4 selectivity (36.3-38.4 and 4.1-4.3 based on Henry's law and 17.88-24.92 and 4.24-5.70 based on ideal adsorbed solution theory, respectively). With the demonstrated properties, the synthesized MPOF-Ads networks display potential for small gas storage and separation that can be used in harsh environments because of their superior physical and chemical stability.

Synthesis a microporous organic gelator and evaluation of organic solvents gelling properties and the separation of crude oil products from water

A new supramolecular and microporous organic gelator, 1-(6-isocyanato)-3-octadecylureahexyl-N-formyl supported on melamine-terephthaldehyde microporous organic framework (1,4-DMB@4Mel@8(ODUHNF)), has been synthesized that has a hydrophobic great tail, many urea functional groups and aromatic ring moieties. It is able to gelate some of organic solvents, especially substituted aromatic compounds in monophasic systems at very low concentrations. Moreover, gelator exhibits high gelation ability for crude oil products (gas, kerosene and diesel) in mono- and bi-phasic systems at very low concentrations. Interestingly, the gelator can be used in five runs of gelation processes without any reduction of its performance.

Melamine-Based Microporous Organic Framework Thin Films on an Alumina Membrane for High-Flux Organic Solvent Nanofiltration.

Microporous polymer frameworks have attracted considerable attention to make novel separation layers owing to their highly porous structure, high permeability, and excellent molecular separation. This study concerns the fabrication and properties of thin melamine‐based microporous polymer networks with a layer thickness of around 400 nm, supported on an α‐alumina support and their potential use in organic solvent nanofiltration. The modified membranes show excellent solvent purification performances, such as n‐heptane permeability as high as 9.2 L m−2 h−1 bar −1 in combination with a very high rejection of approximately 99 % for organic dyes with molecular weight of ≥457 Da. These values are higher than for the majority of the state‐of‐the‐art membranes. The membranes further exhibit outstanding long‐term operation stability. This work significantly expands the possibilities of using ceramic membranes in organic solvent nanofiltration.

Microporous frameworks based on adamantane building blocks: Synthesis, porosity, selective adsorption and functional application

Two microporous organic frameworks based on adamantane (hereafter denoted as MF-Ads) were fabricated through Sonogashira-Hagihara coupling polycondensation of aryl halides and alkynes. Results show that both types of MF-Ad networks had similar porous properties and exhibited excellent CO2 uptake capacity (72.5 cm3 g−1) and CO2/N2 selectivity (59.1) at 273 K and 1.0 bar. Taking advantage of the superhydrophobic wettability of the resulting MF-Ad networks, wire mesh scaffolds were used to fabricate superhydrophobic films with polydimethylsiloxane (PDMS) acting as a binder. These films displayed excellent instant hydrocarbon/water separation efficiency (up to 99.6%), which was maintained at a constant level after five repeated cycles. This work provides a novel insight into the fabrication of microporous organic frameworks and extends their applicability to carbon capture and absorption of hazardous organic pollutants.

Construction of Microporous Organic Nanotubes Based on Scholl Reaction

Herein, we demonstrate a facile method for the preparation of microporous organic nanotubes (MONTs) based on a combination of hyper-cross-linking mediated self-assembling strategy and Scholl reaction by using polylactide-b-polystyrene diblock copolymers (PLA-b-PS) as precursors, in which the PS block forms the microporous organic frameworks of nanotubes through the C–C coupling reaction, while the PLA segment is completely degraded to produce the hollow mesoporous tubular structure. Owing to their high special surface area, robust organic framework and open-ended tubular structure, the obtained MONTs exhibit the outstanding adsorption capacity and efficiency for p-cresol and different organic vapors. Moreover, microporous carbon nanotubes (MCNTs) can be prepared by further carbonization. The resultant MCNTs as electrode materials of a supercapacitor display excellent electrochemical performance with specific capacitances of up to 192 F g–1 at 0.5 A g–1, with capacitance retention of 97% even after 5000 cy...

Hyper-Cross-Linking Mediated Self-Assembly Strategy To Synthesize Hollow Microporous Organic Nanospheres.

Hollow microporous organic nanospheres (H-MONs) are prepared by using polylactide-b-polystyrene diblock copolymers (PLA-b-PS) as the precursor via a hyper-cross-linking mediated self-assembly strategy, in which the hyper-cross-linking PS block forms the microporous organic shell framework, and the degradable PLA block produces the hollow mesoporous core structure. The formation mechanism, morphology, and porosity parameters of the resulting H-MONs are systematically investigated. Moreover, based on the hyper-cross-linking generated rigid microporous organic frameworks, hollow microporous carbon nanospheres (H-MCNs) can be achieved by further pyrolysis progress. The obtained H-MCNs as electrode materials of a supercapacitor exhibit excellent electrochemical performance with specific capacitances of up to 145 F g-1 at 0.2 A g-1, with almost no capacitance loss even after 5000 cycles at 10 A g-1. More especially, H-MONs can be further act as "nanoreactors" for the synthesis of Fe3O4 nanoparticles within hollow cores to construct magnetic core-shell Fe3O4@H-MONs nanocomposite materials. Our strategy represents a new avenue for the preparation of hollow morphology-controlled microporous organic polymers with various potential applications.

Hydrogen bonding controlled catalysis of a porous organic framework containing benzimidazole moieties

A microporous organic framework (JUC-Z12) was synthesized quantitatively from tetra(4-formylphenyl)methane and 3,3′-diaminobenzidine. JUC-Z12 shows high thermal stability (>400 °C), a large surface area (SBET = 750 m2 g−1), a well-defined uniform micropore distribution (1.09 nm) and high Qst for H2 (−8.1 kJ mol−1), CO2 (−29.5 kJ mol−1), and CH4 (−22.2 kJ mol−1). It also exhibits selective catalytic activities in the Knoevenagel reaction, which is supposed to be controlled by hydrogen bonding between substrates and JUC-Z12. The JUC-Z12 catalyst can be easily isolated from the reaction mixture by simple filtration and reused with high activity.

Hydrogen adsorption in microporous organic framework polymer

A microporous organic framework polymer (OFP) based on a polyimide framework exhibits a high surface area (1159 m2 g(-1)) and shows a reversible H2 storage capacity of 3.94 wt% at 10 bar and 77 K, the highest yet reported for an organic polymer.